SELECT 
    TBL_DEPT.DEPT_CODE AS DEPT_CODE,
    TBL_DEPT.DEPT_NAME AS DEPT_NAME,
    TBL_ORDERS.ORDER_NO AS ORDER_NO,
    TBL_CUST.CUST_CODE AS CUST_CODE,
    TBL_CUST.CUST_NAME AS CUST_NAME,
    TBL_ORDERS.ORDER_AMT AS ORDER_AMT
FROM TBL_ORDERS 
    INNER JOIN TBL_DEPT ON TBL_ORDERS.DEPT_CODE = TBL_DEPT.DEPT_CODE 
    LEFT OUTER JOIN TBL_CUST ON TBL_ORDERS.CUST_CODE = TBL_CUST.CUST_CODE
ORDER BY DEPT_CODE ASC, TBL_ORDERS.ORDER_NO ASC